Digest Length Filter

Filter peptide sequences by caller-selected residue length range.

Description

Digest length filtering selects supplied peptide strings by an inclusive length range.

Digest length filtering selects supplied peptide strings by an inclusive length range. This implementation validates canonical content but measures the original string’s length.^[1]

Filter peptide sequences by caller-selected residue length range.

When to use Digest Length Filter

Use this tool to filter peptide sequences by caller-selected residue length range.

Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.

How to use Digest Length Filter and understand its results

Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.
Enter peptideSequences, minimumResidues, maximumResidues using the field table and calculation rules, then run the tool.
Read retainedSequences, rejectedCount. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
peptideSequences	Peptide sequences	list of string	Required
minimumResidues	Minimum residues	number	Required
maximumResidues	Maximum residues	number	Required

Enter peptide strings and positive ordered safe-integer bounds. Validate each after outer trimming and uppercasing, then filter using untrimmed string length. Return original retained strings and rejected count; empty lists are allowed.

retain if minimumResidues≤originalString.length≤maximumResidues

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
retainedSequences	Retained sequences	list of string
rejectedCount	Rejected count	number

json

{
  "input": {
    "peptideSequences": [
      "A",
      "GG",
      "GGG"
    ],
    "minimumResidues": 2,
    "maximumResidues": 3
  },
  "output": {
    "retainedSequences": [
      "GG",
      "GGG"
    ],
    "rejectedCount": 1
  }
}

Limitations and assumptions

Outer whitespace contributes to the filtering length despite being ignored by sequence validation. Remove it before use when residue count is intended. Internal whitespace remains invalid.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Digest Mass Filter: Filter digest peptides by calculated monoisotopic neutral mass. For a complementary task, use Tryptic Peptides: Generate fully tryptic peptides with K/R cleavage blocked before proline.

References

Digest Length Filter — tool.io

Similar or alternative tools

Digest Mass Filter
Filter digest peptides by calculated monoisotopic neutral mass.
Tryptic Peptides
Generate fully tryptic peptides with K/R cleavage blocked before proline.